From: Christoph Lameter <[EMAIL PROTECTED]> Date: Fri, 20 Apr 2007 17:25:16 -0700 (PDT)
> On Fri, 20 Apr 2007, David Miller wrote: > > > That's correct for hardware interrupts. It will, however, work for > > soft interrupts and similar contexts. > > Is there really a significant gain? It seems that such logic would be more > expensive than an atomic operation. > > local_t is saving atomic overhead right? It does no good for cacheline > contention etc. Adding another int will increase cache footprint. > Another rat hole? We've been doing it for SNMP statistics in the networking for a long time and I'm pretty sure it's better than an atomic at least on sparc64 where the atomic is 40 cycles minimum on several processors. I really don't want to start using local_t's all over the damn place if they are implemented as atomics until they are proven to be faster which I doubt they are on sparc64 for one. - To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
